1. Field of the Invention
The invention relates to a method, and more particularly to a method of preparing oil-absorbing fibers.
2. Description of the Related Art
In recent years, environmental pollution caused by oil from oily sewage, exhaust gas, waste liquid, and leakage of oil tankers has been increasingly serious, among which, industrial wastewater discharge accounts for 30%, and leakage of oceanic oil tankers accounts for 45%. Faced with the deteriorating environment, research on developing effective oil recovery technologies, materials for purifying oil-bearing industrial wastewater, and high quality oil absorbing materials has become a major topic.
High oil absorbing resin is a kind of self-swelling polymer having a low degree of crosslinking and consists of lipophilic monomer. The resin molecules form a three-dimensional cross-network structure in a manner of chemical, physical, and ionic crosslinking, particularly in a manner of chemical crosslinking.
In 1966, U.S. Dow Chemical Company produced a nonpolar high oil absorbing resin using alkyl vinyl as a monomer and divinylbenzene as a crosslinking agent (JP 45 27081, 1970).
In 1973, Mitsui Oil Exploration Co., Ltd., Japan produced a polar resin having a solubility of more than 9.8 g using alkyl methacrylate or alkyl styrene as a monomer and crosslinking the monomers (JP 50 15882, 1975).
In 1989, Murakami Corporation, Japan produced a polar high oil absorbing resin, namely, a copolymer of vinyl acetate and vinyl chloride, using triisopropylphenyl peroxide as a crosslinking agent (), Functional Materials, 1990, 10(11): 43-49).
In 1990, Nippon Shokubai Co., Ltd. produced a medium-polar high oil absorbing resin, namely, a low crosslinked acrylic polymer having long chain alkyl at side chain thereof, using acrylic acid as a monomer (Market Data on Functional Materials, Functional Materials, 1991, 11(7): 41-47).
However, in China, researches on high oil absorbing resin are initiated late and mainly conducted by a few of universities and research institutes. Oil absorbing materials such as polynorbornene resins (Songbo, Preparation and Application of Polynorbornene, Liaoning Chemical, 1986, 6: 28-32) and polyurethane foam (Translated by Lv Hongjiu, High Oil Absorbing Polyurethane Foam, New Chemical Materials, 1994, 6: 18-22) are studied. By using methacrylic acid series as starting materials (Lu Jianmei, et al., Preparation and Properties of Oil Absorbing Complex by Microwave Radiation, Chemical World, 1999, 2: 86-89), benzoyl peroxide (BPO) (Liu Derong, et al, Preparation of Self-Swelling Oil Absorbing Resin Synthesized by Crylic Acid Series, New Chemical Materials, 1997, 4: 37-39) and persulfate (Cao Aili, et al, Preparation and Properties of Oil Absorbing Resin Synthesized by Crylic Acid Series, Polymer Materials Science & Engineering, 1999, 2: 38-40) as an initiator, and 1,4-butylene glycol diacrylate (Lu Jianmei, Zhu Xiulin, Preparation and Properties of High Oil Absorbing Resin Synthesized by Binary Copolymerization, Polymer Materials Science & Engineering, 1995, 2: 41-45), ethylene glycol diacrylate (Zhu Xiulin, et al, Preparation and Properties of High Oil Absorbing Resins, Polymer Materials Science & Engineering, 1995, 1: 19-23), and diene as a crosslinking agent (Jiang Bibiao, et al, Preparation and Properties of High Oil Absorbing Resins, China Synthetic Resin and Plastics, 1996, 2: 37-39), by method of suspension polymerization (Lu Jianmei et al, Studies on High Oil Absorbing Resins Synthesized by Methacrylate, Petrochemical, 1995, 3: 176-179), emulsion polymerization (Cao Aili, et al, Preparation and Properties of High Oil Absorbing Resins Synthesized by Crylic Acid Series, Polymer Materials Science & Engineering, 1999, 2: 38-40), or microwave radiation (Lu Jianmei, et al, Preparation and Properties of Oil Absorbing Complex Through Microwave Radiation, Chemical World, 1999, 2: 86-89), high oil absorbing resins having an oil absorbing rate of 10-30 are produced.
However, current studies on oil absorbing materials mainly focus on granular resins. Granular materials limited on its shape, have disadvantages such as slow absorbing speed and low oil absorbing rate, thereby resulting in a limited application. Nowadays there are less research reports on oil-absorbing fiber at home and abroad. China Patent Publication Number CN 1584148A (Xiao Changfa, Feng Yan, et al, Tianjin Polytechnic University) disclosed a method for preparing a polymethacrylate oil-absorbing fiber by semi-interpenetrating network technique and wet spinning. The oil-absorbing fiber has large oil absorbing area, is easy for recovery, and can be processed into various shaped products as needed. So the fiber has a wide application range, and if used in industry, it will play a positive role for treating water resources. Conventionally, in order to synthesize high oil absorbing resin, a single chemical crosslinking agent, e.g. divinylbenzene is used. Although the resultant resin has a perfect chemical crosslinking structure. It's neither soluble nor meltable, resulting in a difficulty for preparing fibers. Furthermore, in the method of preparation of oil-absorbing fibers disclosed by China Patent Publication Number CN 1584148A, polymers are synthesized step-by-step, and the obtained fibers need to be crosslinked by heat to form a chemical crosslinking structure. Therefore, the method is very complicated, and the fibers made by wet spinning have bad mechanical properties.